The present disclosure relates to the generation of electrical power for large-vehicle transport refrigeration units (TRU) such as semi-trailer reefers. A generator is mounted to the vehicle frame or axle carriage and driven by a wheel-pulley system. Translational motion of the heavy vehicle produces electrical power. A solar panel is installed on the roof of the battery powered TRU to charge the battery when the unit is stationary or in motion.
Recent developments in battery powered transport refrigeration units such as semi-trailer reefers, demonstrate a need for an efficient and economical power generation method capable of running the electrical refrigeration unit and charging the battery. The refrigerated food product carried by these reefers is at risk when unscheduled delivery delays are encountered. The reefer can stop cooling because of limited battery capacity. This invention provides backup power to keep the reefer running. If battery power runs out the reefer trailer can be pulled down the road to generate enough power to run the reefer and recharge the battery thus preventing the loss of the perishable-refrigerated food. This also allows for battery pack size to be reduced or minimized. The high cost of battery packs can be a deterrent for high-volume deployment of the technology. This disclosure provides a method for assisting high-volume deployment.
Prior art systems mount a generator directly on the trailer axle or make use of an axle-differential combination to drive a frame-mounted generator with a drive shaft.
The axle-mounted generator is undesirable because the generator takes excessive punishment from road vibration and mechanical shock. Every time the wheel mounted to the axle hits a bump in the road the movement is transmitted to the generator resulting in poor generator reliability.
The axle, differential and driveshaft combination solves this problem because the generator can be mounted solidly to the trailer frame. However, this system is heavy, expensive and requires changing the trailer axle to a truck type axle with a differential.